


unison

by fan_nerd



Category: Haikyuu!!
Genre: Future Fic, M/M, PWP, mutual voyeurism
Language: English
Status: Completed
Published: 2015-05-31
Updated: 2015-05-31
Packaged: 2018-04-01 07:20:55
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,141
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4010890
Author URL: https://archiveofourown.org/users/fan_nerd/pseuds/fan_nerd
Summary: <blockquote class="userstuff">
              <p>Really, when they keep running into each other in such compromising positions and <i>trying</i> to avert their eyes, it's only sensible that the two couples cut to the chase and have a contest.</p>
            </blockquote>





	unison

Admittedly, the move is a pretty great idea—in  _theory_.

They're all on the national team. Their commutes stink. They're four handsome guys in two successful relationships, and they have very little to lose.

Kageyama has impatiently cursed at the microwave a hundred times. Oikawa doesn't even know how to do his laundry.

Needless to say, it's Hinata and Iwaizumi who take care of the moving details.

It's a two-bedroom place. Why get a four when they all know the deal?

Oikawa and Kageyama, predictably, fight a lot. Even after two years as teammates on the national team, they're still thirteen year olds at heart. Iwaizumi says this age is an overestimate; Hinata agrees. If one of them so much as spills coffee on the countertop, they start a verbal match of superiority in setting, where they would recount successful points that their spiker boyfriends had scored. From there, the arguments would devolve into childish fights about who had a better boyfriend, and Kageyama usually loses in terms of vocabulary, because his only ways of complimenting Hinata are ways that sound vaguely insulting.

Of course, there are nights that are silent and peaceful and the four of them think,  _hey, this wasn't such a bad idea after all_.

On an everyday level, they get along fine despite the petty clashes and other minor disagreements. They even manage to be polite about their statuses as  _couples_. Mostly.

Oikawa accidentally stumbles onto the scene of Hinata plowing into Kageyama, who's laid out on their little kitchen island and keening wildly, squirming like he can't keep his damn legs still. He sees Hinata lick his lips and whisper, "Hot, you're  _so_  goddamn hot like this, Kageyama, I could do this forever. Just thinking about if somebody saw you like this, red and wild and  _begging_ , clenched around me so tight, I can't  _stand_  it."

"Shut  _up_ ," Kageyama breathes, "I swear to god," he gives his boyfriend a deep kiss, then gasps, "I'll  _kill you_ , Hinata, fucking  _there_.  _Gonna, gonna, gonna._ "

The brunette smartly sneaks back out of the door, but not before hearing Hinata purr, " _Come_  then, Kageyama."

On the other end, Kageyama passes out at midday, calls out of work, and opens the bedroom door just enough to see his roommates fucking in the bathroom.

"This is  _absolutely_  your worst idea yet," Iwaizumi's holding Oikawa in his lap while they sit on the toilet. The brunette squirms and his junior can see the taller male's dick bouncing as he pushes himself up and down in the tight space, face flushed and lips swollen from biting them. "Are you happy now? Do you think this is  _sexy_? Is it everything you wanted?"

"You are  _so_ ruining the mood right now, Iwa," Oikawa huffs, digging his nails into his boyfriend's legs. The muscles in his legs tighten as he clenches and Iwaizumi leans forward, groaning into his shoulder. "Can't you tell me how nice I look with legs spread out for you? I could be sitting here, cleaning my asshole for you every morning, waiting for you come in and say,  _I want you, I can't wait, let's have a round before practice._ "

"What, that's all you want me to say?" Iwaizumi snorts through his nose, wrapping strong hands around Oikawa and lifting the other man up and down on him, sliding thick fingers across the brunette's muscular chest. "I love the way your ass looks like this—it's all red from where I'm holding you, and you're so tight,  _goddamn_  it. Stop. Also, did you know you're flashing your dick right out the doorway? Hinata and Kageyama could come home any time, but then you'd just show off, wouldn't you?"

"Ah, damn," Oikawa moans, "I'd love to see the look on the bastard's face, Iwa. I could come on his shoes."

"You kinky little shit," Iwaizumi lifts and lowers the brunette again; Oikawa curls his toes through an orgasm.

Kageyama very tentatively closes the door and never  _ever_  lets on that he was home that day.

With all the tension in the place,  _something_  has to give.

They win a match. The four of them ride out an endorphin high that has their blood singing and their hormones thrown spectacularly out of whack.

Oikawa, for all his usual bravado, is rather tentative about  _this_  sort of thing.

Sure, he can talk dirty to Iwaizumi all he wants, but then, he's known him for his whole life. His boyfriend knows he's just silly, frivolous Tooru, who is easily jealous of 'geniuses' and is insecure about everything from his volleyball to his hair. That night, he simmers in silence, too scared to fuck things up when everything is so good.

Kageyama wouldn't approach the topic with a hundred meter pole.

It isn't that he's a prude so much, but more that he's not exactly that creative and he wouldn't know how to go about bringing it up in the first place. He gets embarrassed over his boyfriend threatening to call him by his first name in the supermarket. The idea of anything more absurd than Hinata's desire to have him on every surface in the apartment has probably never crossed his mind. He sleeps early, as he always does after games, but he tosses and turns, throwing the covers off in the middle of the night.

This leaves it to Iwaizumi and Hinata to take the initiative.  _No surprise_. Since they can't sleep, they take the time to create a plan. Kageyama and Oikawa will be informed of the proposal tomorrow.

The two of them have high expectations.

/ /

The idea is initially met with resistance.

Oikawa looks pretty damn repulsed. Kageyama doesn't look too happy about it either.

But then, Kageyama is so fucking weak to Hinata pouting and begging, and Oikawa is hard-pressed to ignore the intensity in his best friend's eyes. Not only that, but Iwaizumi so rarely asked for  _anything_ , especially not of this variety.

Oikawa breaks first, heaving a sigh. "If Tobio-chan agrees, I'll do it on  _one_  condition. We make it a contest."

Kageyama's head whips towards brunette. "What."

"Ooh, I like the sound of that," Hinata chirps, eyes bright and smile brighter. "What kind of contest?"

"Anything goes. We'll record everything—" at this, Iwaizumi snaps,  _"What,"_  and Oikawa continues, "For  _private_  purposes only, Iwa, sheesh. As I was saying, we'll record it and see who won. Equal rounds! We'll tally orgasms, moans, scratches, kisses, and so on. We'll come up with a proper point system later, but the only way I'll be into this is if I can gloat about another victory over him!"

"Are you  _stupid_?" Kageyama sputters, turning red down to his collarbone. "I, that's,  _uh._ "

"Ah, look, you broke him," Iwaizumi deadpans.

"I think he's just processing," Hinata gleefully remarks. "Give him time."

Iwaizumi sighs and puts one hand on his hip. "Look, we've all been watching. Let's just get that out of the way." The other three nod somberly. "We've been turning away because we think it's not right or that we shouldn't be looking, but hey, I'll be the first to admit, I've caught you two going at it, and it's kinda hot."

"I  _know_ ," Hinata drawls dreamily. "I could've sworn I heard you two having sex and I could hardly wait for Kageyama to get home. I imagined us doing it against the wall while you two did, and damn. The idea alone."

Kageyama can't deny the fact that he's had similar thoughts and similar feelings and right now he's feeling like it wouldn't really take a whole lot to make him fully hard.  _Damn._

Oikawa kind of wants to force Iwaizumi to put his calloused hand down his pants now because  _shit,_  is this whole idea sounding better by the minute or what?

"So?" Iwaizumi starts, cocking his hips.

"Are you in?" Hinata bounces on his heels excitedly.

Kageyama and Oikawa share a look that is mostly a glare, but it burns with something that is partially shame and mostly lust. "We're in."

They make a plan for next Thursday, a day with no practice, no matches coming up soon, and no work for any of them, either through rescheduling or otherwise their typical days off.

The expectation thrums under their skin.

/ /

Hinata is super fucking restless on the best of days, so by Thursday morning, he's a goddamn wreck.

He's stocked up on everything. The kind of unscented lube his boyfriend likes; loose condoms that didn't give either of them burns or rashes, even though they hardly use them nowadays. He's even shaved and gotten a couple of  _bed toys_  with his play money, but he's fairly certain that Kageyama will want nothing to do with them, no matter what kind of challenge Oikawa makes him rise to.

Damn it, he just wants his roommates to come home and stop acting like this can wait.

Oikawa returns first, looking unreasonably well rested, glowing with a sense of childish pride. He thinks he's already won. The thrill of his arrogance just makes Hinata's blood pump faster.

The brunette even has a camcorder, as promised. He sets it up and Hinata legitimately bounces out of his chair. "Relax," Oikawa murmurs, smirking proudly. "You'll need that energy later."

" _Gahhh_ ," Hinata groans, digging his palms into his eyelids. "How could you guys all go out and focus on errands and shopping right now?"

"Oh, I'm  _sure_  they're out for more than just groceries." Oikawa holds up what had been in his bag, something teal and lacy and horrendously enticing. "Don't think you're the only one committed here, shorty."

"Lace," the redhead breathes reverently. " _God_. What I wouldn't pay."

The taller man basks in the compliment. "I'm going to tease Tobio-chan with that info later, but I have to see Iwa-chan's reaction first."

Hinata would feel bad, but Oikawa humiliating Kageyama about the underwear he purchased would likely lead to his embarrassment at having never thought of such a thing, and he might even buy his own pair of lace undies just to spite the brunette.

For Hinata, it's a win-win.

Kageyama walks in next, looking outwardly disgruntled and composed, but Oikawa can tell he's not quite steady and Hinata can see that his collarbone and ears are tinted pink.

 _He's excited, he's_ _ **so**_ _fucking excited_ , Hinata thinks, growing increasingly more restless.  _His ears are wiggling and his lips are quirking, oh god, he's so cute._

His boyfriend doesn't know what's in the bag, but if it can draw that kind of expression out of Kageyama, he's all for it.

When Iwaizumi enters last, Oikawa studies him for a moment and then smiles in approval. Iwaizumi confidently sweeps across the room, showing off his muscles in a loose tank top, locking eyes with  _his_  boyfriend and smirking just a bit. His hands are in his pockets a moment later when he pretends to be stern and Oikawa thinks,  _just who do you think you're trying to fool?_ He licks his lips slowly and Iwaizumi stares, enraptured.

"Why the hell are we all still dressed?" Hinata loses patience first. "Everyone go get all your shit, and meet back here in fifteen!"

Fifteen minutes later, they reconvene in the living room to move all the spare furniture out of the way and roll out two futons. Oikawa has even gone lengths to procure a tripod, so he sets up the camera near a plug so it won't lose power and double-checks the memory.

"You think we can keep at it for two hours?" Iwaizumi sends him a dry look and Oikawa sticks out his tongue. "You never  _know_."

Kageyama is surprisingly the first to mumble, "Hinata and I have had sex for an hour before." Hinata colors, smiling sheepishly.

Even Iwaizumi has to whistle at that, but Oikawa gets fired up, furrowing his brow and wearing a challenging smile. "Well, now we  _have_  to go for an hour an a half, Iwa-chan!"

" _Holy shit_ ," Iwaizumi mutters, not exactly angry but not exactly pleased either. "What kind of machine do you think I am?"

Kageyama snorts out of his nose. "It  _was_  pretty crazy."

"Iwa-chan, are you just gonna let him look down on us like this?" Oikawa pouts.

"I  _hate_  you," Iwaizumi grumbles, groaning into his palm. "If we can't move tomorrow, I'm forcing you to write a letter of apology."

"We can't lose to him, dumbass," Kageyama says sternly, and Hinata scoffs.

"Like I didn't know that, duh."

There is an awkward pause where they all sit around with small bags of stuff around the double-futon set on the floor, but they aren't really sure how to begin this whole…weird… _thing_.

Once the pause settles, Oikawa is the one clear his throat and say, "Well, unless  _somebody_  kisses someone, this is going to be a very boring sex-tape." That eases them all into laughter, but they're still rather hesitant.

Kageyama, surprisingly, is the first one to kneel on the futon. He drags Hinata down with him. "Do you still want to do this in front of them?"

Hinata rolls his eyes. "That was literally the whole point of this, Kageyama."

The dark-eyed setter sucks in a deep breath and waits until the redhead leans into him before huffing against a tan cheek. "Okay."

Iwaizumi sits on the second futon, patting the space in his lap for Oikawa to come join him when the brunette wants to, but for the moment, Iwaizumi watches the two of them with shallow breaths.

By now, Hinata and Kageyama are only doing some petting and making out, but seeing Iwaizumi so blatantly focused on the two of them slipping into the mood makes Oikawa flush. The older setter sinks to his knees and lazily drapes himself over his boyfriend's shoulders. "You don't have to stop watching," he says, kissing Iwaizumi's back, flicking his eyes between his partner's eyes and the two men in front of them.

"Mm," Iwaizumi leans into his touch pliantly as Hinata slides a hand up Kageyama's shirt and bites a hickey into younger setter's elbow. Kageyama's back arches in time with Oikawa's fingers raking down his spine and he shivers.

"Don't just look at me, Kageyama," Hinata breathes the words over his boyfriend's ribcage. "Iwaizumi-san's expecting a show, you know."

"Then  _give_  him one," Kageyama hisses, pulling Hinata's hips down on him while holding gazes with Iwaizumi. "Weren't you the one the most excited for this? What are you waiting for, idiot?"

"What indeed," Oikawa laughs, casually unbuttoning Iwaizumi's trousers and earning a happy grunt in response. "He's not hard just yet, boys. Turn over here a little more while you lift up his shirt, shorty."

"I'm trying, but Kageyama's all lanky and annoying," Hinata huffs as he very much un-sexily peels off the button down and reveals a pale chest. Kageyama scowls at the words. "Sorry, his chest isn't that exciting." He's got a six-pack—it comes with the territory of being a national athlete—but their sport is focused on the lower body, so the redhead continues, "His thighs and his ass are  _so_  much better, I promise."

"Competitive in all the same categories, then," Iwaizumi chortles and Oikawa indignantly snorts. "Luckily we're not into the muscly ones, huh?"

"They'll do," Hinata laughs airily, but Kageyama and Oikawa are getting impatient with the teasing words.

Since the elder players are currently playing voyeur, Oikawa works on coaxing Iwaizumi to full hardness. He knows exactly how to stroke him, when he should bite his ear and wrap his legs around the sturdier male's abdomen. He presses his calloused fingers lightly underneath Iwaizumi's member, sliding them over and across his thighs before biting his neck,  _deeply_ , and earning a lewd moan as his reward. Once Iwaizumi's hard, he keeps stroking, licking his way down his spine, keeping his hands moving until Iwaizumi gets impatient enough to say, " _Enough_ ," putting a hand in Oikawa's hair. "I'd like you to finish what you started, please."

"So gruff," Oikawa hums at the pressure of his locks being tugged. "Pull harder and I'll service you on the house."

"We're dating. It's always on the house, shithead."

Oikawa blows air on him, smiling coyly. "Be nice to me or no treat for you."

At that, Iwaizumi smirks and says, "Fine. I still remember how to get myself off."

"Cruelty! Boyfriend cruelty!"

" _You're_  the one who wants to put my dick in your mouth." On another day, Oikawa might enjoy watching the stoic Iwaizumi get himself off, slow and steady, voice low and keening, but today, he has a duty to outclass his old junior. He gives up playing cute and wiggles his loose pants lower, flashing his ass in Kageyama's general direction as he relaxes his jaw and lets Iwaizumi slide in, hot and hard. Flashing dark eyes up, he trills a sound in his throat to see his crowd's reaction and is met with moans all around.

 _Perfect_.

Hinata cants his hips against Kageyama's, letting a low moan escape against the shell of the dark-haired man's ear. When he looks at their elders, both he and his partner beneath him lock up.

_The lace._

Iwaizumi pushes into the heat of Oikawa's mouth a little too hard and gasps,  _"Hoooooly fuck_." With a low, animalistic groan, he pulls the brunette off of him and heaves, "You glorious  _bastard_."

Hinata shucks himself out of his pants, unable to stay calm after watching more of their brilliant exchange. "God," he breathes, reaching to take off Kageyama's pants as well. They're both clearly enjoying the view of Oikawa's panty-clad rear, the round lines of admittedly shapely butt stretching against the sheer material of the teal undies. "Kageyama,  _god_ , please suck on my fingers for a sec while I get the lube. I was gonna take this first round slow, but that was dirty."

"Yeah," Kageyama takes his slim fingers into his mouth without complaint, sounding winded and looking flushed as all hell. He can't exactly tear himself away from what their colleagues are doing either. "Yeah, okay." He sucks on them, tasting strawberries or lemon juice or both and  _holy hell_  had Hinata dipped his hands in something before they met back up in the living room? It's not like doing this is his favorite activity in the entire world, but damned if he doesn't love strawberry lemonade. He lightly bites Hinata's middle finger in a daze. Hinata runs his fingers over Kageyama's teeth before dragging his damp hand down his partner's backside while it's still warm.

He leans down so his head is at the backside of Kageyama's thighs, and he presses his hands upwards against tender flesh until the dark-haired man trembles. He presses the cheeks of Kageyama's ass together in front of their audience for show so they can watch the alluring curve of his spine as Hinata flicks his fingers and tongue down it, planning on eating him out.

"You stone-faced  _asshole_ ," Hinata exhales incredulously. "What the hell. How long have you had this in here?"

Kageyama manages to groan, "Since I bought it this morning?"

"I can't believe it." The redhead twists the plug with a flick of his wrist and Kageyama's back bends. From just next to them, Iwaizumi and Oikawa pause mid-blowie to suck in air, amazed. Hinata slicks up his hand before crooking a finger in him around the plug, frantic to see Kageyama squirm and moan. "I didn't know you liked toys."

Looking thoroughly embarrassed, Kageyama mutters, "I like everything with you."

Hinata  _can't_  stop smiling about that. "Damn. That's adorable. I should've asked earlier. I bought more."

When his finger brushes just around his prostate, Kageyama clenches fingers in the futon and throws his head back in a silent scream. "Fuck!"

At that, Oikawa decides to up his game and switch positions, grinding his lace-covered ass against his partner and leaving his flushed cock peering out of the underwear. "I'm impressed, Tobio-chan. You're much more lewd than I would've given you credit for."

Iwaizumi leans back for a moment, loving the friction of his member against the lace. He too pulls lube out of his bag along with a soft leather belt. Oikawa obligingly offers his wrists to him behind his back. He licks his lips once Iwaizumi has finished tying him, large fingers darting under the lace with a heady moan. "C'mere, Sit on my face."

At the same time, Hinata pulls the toy out of Kageyama, fisting his tall partner's member in a small hand and flicking his tongue into him. Oikawa and Kageyama both howl in pleasure as their partners taste them, staring at each other with glossy eyes and various states of consensual quasi-humiliation.

It is  _unbearably_  good. Iwaizumi gets tired of just smelling and licking Oikawa's ass, and he slicks his fingers up, spreading the brunette's asshole around the lace. The underwear is starting to stretch into a pertinent v between Oikawa's cheeks because his dick won't stay in them anymore and Iwaizumi pants with the weight of Tooru's thighs on his chest. "God, I wish you could understand how hot this is."

Oikawa, who's watching Kageyama come undone at Hinata's ministrations, drool dribbling down his junior's chin, coils fingers gently in Iwaizumi's hair with his limited mobility. "Oh, don't worry. I understand plenty."

Since they've been on the verge for what feels like ages, the four of them come quickly, but the night is young and they still have well over an hour left to kill.

When Hinata and Kageyama have sex, they do it doggy style the first time, and Kageyama balances himself on the futon just in front of Oikawa, who's riding Iwaizumi.

They all go sixty-nine for mutual blowjobs around the forty-minute mark; Hinata breaks out the toys, Iwaizumi unbinds Tooru's wrists in favor of gagging him, but not for long, because he adores his filthy mouth, and Kageyama howls like a goddamn animal when he's at climax, pushing, pushing,  _pushing_  Hinata to go faster and trusting him like he'd never trusted anyone before.

The word  _love_  is careful on their lips, in such a special space, but between rounds there is reassurance and double-checking to make sure everyone's on the same page. There's loving glances and getting hot and bothered over the others, and languid hand jobs and sloppy kisses and overall it is just a marathon of sex for about an hour before Iwaizumi and Hinata fucking crap out, but Kageyama and Oikawa refuse to quit.

Hinata offers himself to Kageyama—he's done it before, he wants to try, he's open-minded, but Kageyama doesn't want to. Oikawa has had sex with Iwaizumi, but they don't have as much chemistry that way, he swears—he talks more to cover up his inexperience, but he's alright with being filled with Iwaizumi's cock for the rest of god-forsaken life.

The session ends up in a lot of sleepy cuddling and murmurs about how fucking awesome this idea is.

They also agree that they'll never do this again.

Well, the sex competition marathon _thing_.

They're  _definitely_  going to watch each other have sex again.

In their apartment, it's a given.

/ /

A few weeks later, after the bitter point allocation that leaves Kageyama and Oikawa fired up, Iwaizumi has a front row seat while Hinata has Kageyama up against the wall in his and Oikawa's room, a hand wrapped firm around himself while they go at it and Kageyama's eyes grow glossy. Hinata pushes into him again, knocking knees, and the sheen of the sweat on their backs compliments Iwaizumi's finish with a happy sigh.

Oikawa openly drools over their kitchen table one morning when Hinata finds them, so he gets hot under the collar and rubs one off before he goes to work. When he hears the brunette snarl and sees the semen leak onto the table, he has to stop himself from drooling as well in response, sending Kageyama a snap of the three of them and texting him the situation.

Two nights later, as Hinata had been hoping for, Oikawa and Iwaizumi have sex against the bedroom wall adjacent to their room, and the redhead cajoles for he and Kageyama to do the same. Kageyama takes pictures of his and Iwaizumi's backs later, even as he jokes that Hinata can't even lift him that high and that his thighs did most of the work, to which Oikawa snarks back in response that Iwaizumi is  _amazing_  because he handled most of the heavy lifting all by himself.

The two of them devolve into a childish fight about how great the sex was anyways, which leads to comparing boyfriends, and side jobs and setting.

Hinata and Iwaizumi just sigh, making a pot of tea and sharing a look.

The living situation's not perfect, but hey, it works for  _them_.

* * *

  
  


**Author's Note:**

> apparently i can't write hinakage without writing iwaoi, so i figured if i'm going to hell why not go all the way??? ¯\\_(ツ)_/¯


End file.
